The big question: How do we determine when sanctions have failed? At what point would Americans say, “We’ve done all we can and it hasn’t worked, so let’s fire up the bombers”?

Economic sanctions to stop Iran from developing nuclear weapons aren’t effective, American voters say 60 – 33 percent, and 50 percent of voters say the U.S. should take military action to stop Iran’s nuclear program if sanctions don’t work, according to a Quinnipiac University poll released today.

American voters tell the independent Quinnipiac (KWIN-uh-pe-ack) University poll 55 – 36 percent that the U.S. should not take military action against Iran. But 25 percent of those opponents shift to support military action if sanctions fail.

The combined result is 50 percent in favor of military action if sanctions fail, with 38 percent opposed.

Which is all well and good, but — again — when do Americans perceive sanctions as having failed? If Iran acquires nuclear weapons despite our sanctions? If by a predetermined amount of time the country’s nuclear program still hasn’t been crippled? Should we continue to try sanctions even after Iran has nuclear capabilities, as we’ve done with North Korea (which, unlike Iran, China largely keeps in check)?

Other numbers from the poll:

• Barack Obama’s approval rating is just 44%. 50% disapprove.
• A plurality (48-40) say the Supreme Court should overturn ObamaCare. That includes 86% of Republicans, 19% of Democrats, and 45% (a plurality) of Independents.

Summary: Obama remains unpopular, ObamaCare remains very unpopular, and Americans are now considering the possibility of a military strike against Iran.